The present invention relates to a dual lock seat reclining mechanism, in particular to the left and right interlocking structure in a mechanism in which a symmetric pair of left and right seat reclining devices each with an internally toothed portion are placed on the left and right sides of a seat cushion of a vehicle such as a car.
Many conventional vehicle seat reclining mechanisms are of a dual lock type having a left and right pair of seat reclining devices each with a so-called externally toothed portion. The left and right devices on the left and right sides of the seat cushion are connected by a rotatable connection pipe so that operation of one device causes operation of the other device. The left and right ends of the rotatable connection pipe are operatively connected with the left and right devices, respectively, by left and right links. Each of the left and right devices has a lock mechanism of an external tooth type or an internal tooth type.
It is an object of the invention to provide a dual lock seat reclining mechanism having a more-reliable and less-obstructive linkage between left and right locks.
According to the present invention, a dual lock seat reclining mechanism comprises:
a rotatable connection member extending from a left end to a right end; and
a left mechanism connected with the left end of the connection member and a right mechanism connected with the right end of the connection member.
Each of the left and right mechanisms comprises;
a base plate adapted to be fixed to a seat cushion, the base plate comprising an elongate arc hole;
a swing tooth plate adapted to be secured to a seat back, the tooth plate having a recess formed with an internally toothed portion;
a center shaft supporting the tooth plate rotatably relative to the base plate;
a lock tooth member having an externally toothed portion for engaging with the internally toothed portion of the swing tooth plate;
an operation member for moving the lock tooth member in the guide portion of the base plate toward and away from the internally toothed portion of the swing tooth plate for engagement and disengagement between the externally toothed portion and the internally toothed portion, the operation member comprising a pin; and
a link comprising an inner portion connected with the connection member, and an outer bent portion received in the elongate arc hole of the base plate and engaged with the pin.